Imaging members

ABSTRACT

An imaging member including a metal or metallized substrate; an undercoat layer comprising a polymer resin and a near infrared absorbing component that absorbs at an imaging member exposure wavelength and has a high molar extinction coefficient; and one or more additional layers disposed on the undercoat layer, wherein the additional layer or layers comprise a charge-generating component and a charge-transport component.

BACKGROUND

The present disclosure relates generally to imaging members forelectrophotography. Specifically, the disclosure teaches imaging membershaving a substrate, which can be a metal or metallized substrate inembodiments. In embodiments, the disclosure relates to imaging membershaving an undercoat layer having a polymer resin and a near infraredabsorbing component that absorbs at an imaging member exposurewavelength and has a high molar extinction coefficient. In embodiments,the component is soluble in an undercoat layer solvent. In additionalembodiments, one or more additional layers are disposed on the undercoatlayer, and the additional layer or layers may include acharge-generating component and a charge-transport component.

In electrophotography, an electrophotographic substrate containing aphotoconductive insulating layer on a conductive layer is imaged byfirst uniformly electrostatically charging a surface of the substrate.The substrate is then exposed to a pattern of activating electromagneticradiation, such as, for example, light. The light or otherelectromagnetic radiation selectively dissipates the charge inilluminated areas of the photoconductive insulating layer while leavingbehind an electrostatic latent image in non-illuminated areas of thephotoconductive insulating layer. This electrostatic latent image isthen developed to form a visible image by depositing finely dividedelectroscopic marking particles on the surface of the photoconductiveinsulating layer. The resulting visible image is then transferred fromthe electrophotographic substrate to a member, such as, for example, anintermediate transfer member or a print substrate, such as paper. Thisimage developing process can be repeated as many times as necessary withreusable photoconductive insulating layers.

In electrophotography, an electrophotographic substrate containing aphotoconductive insulating layer on a conductive layer is imaged byfirst uniformly electrostatically charging a surface of the substrate.The substrate is then exposed to a pattern of activating electromagneticradiation, such as, for example, light. The light or otherelectromagnetic radiation selectively dissipates the charge inilluminated areas of the photoconductive insulating layer while leavingbehind an electrostatic latent image in non-illuminated areas of thephotoconductive insulating layer. This electrostatic latent image isthen developed to form a visible image by depositing finely dividedelectroscopic marking particles on the surface of the photoconductiveinsulating layer. The resulting visible image is then transferred fromthe electrophotographic substrate to a member, such as, for example, anintermediate transfer member or a print substrate, such as paper. Thisimage developing process can be repeated as many times as necessary withreusable photoconductive insulating layers.

Electrophotographic imaging members (i.e. photoreceptors) are wellknown. Electrophotographic imaging members are commonly used inelectrophotographic (xerographic) processes having either a flexiblebelt or a rigid drum configuration. These electrophotographic imagingmembers sometimes comprise a photoconductive layer including a singlelayer or composite layers. These electrophotographic imaging memberstake many different forms. For example, layered photoresponsive imagingmembers are known in the art. U.S. Pat. No. 4,265,990, which is totallyincorporated by reference herein, describes a layered photoreceptorhaving separate photogenerating and charge transport layers.

Photoconductive photoreceptors containing highly specialized componentlayers are also known. For example, a multilayered photoreceptoremployed in electrophotographic imaging systems sometimes includes oneor more of a substrate, an undercoating layer, an intermediate layer, anoptional hole or charge blocking layer, a charge generating layer(including a photogenerating material in a binder) over an undercoatinglayer and/or a blocking layer, and a charge transport layer (including acharge transport material in a binder). Additional layers such as one ormore overcoat layers are also sometimes included.

Photoconductive or photoresponsive imaging members are disclosed in thefollowing U.S. Patents and U.S. Patent Applications, the disclosures ofeach of which are totally incorporated by reference herein, U.S. Pat.Nos. 4,265,990, 4,419,427, 4,429,029, 4,501,906, 4,555,463, 4,587,189,4,709,029, 4,714,666, 4,937,164, 4,968,571, 5,019,473, 5,225,307,5,336,577, 5,471,313, 5,473,064, 5,958,638, 5,645,965, 5,756,245,5,797,064, 5,891,594, 6,051,351, 6,074,791, 6,194,110, 6,656,651,commonly assigned, co-pending U.S. Patent Application of John S.Chambers et al., Ser. No. 10/758,046, filed Jan. 16, 2004, entitled“Thick Intermediate and Undercoating Layers for ElectrophotographicImaging Members and Method for Making the Same” and commonly assigned,co-pending U.S. Patent Application of Jin Wu et al., Ser. No.11/133,979, filed May 20, 2005, entitled “Imaging Member”. Theappropriate components and process aspects of the each of the foregoingU.S. Patents may be selected for the present disclosure in embodimentsthereof.

Current issues in xerography include the occurrence of ghost imageeffects on printed substrates. For example, known photoconductors arebelieved to be susceptible to carrier injection from the substrate intothe photosensitive layer such that the charge on the surface of thephotoconductor may be microscopically dissipated or decayed. This oftenresults in production of a defective image. Another problem relates tothe phenomenon referred to as transfer ghost, which is a transfercurrent induced ghosting defect on an image believed to be caused byinternal charge migration and/or charge injection from the top surfaceor substrate.

SUMMARY

Embodiments disclosed herein include an imaging member comprising ametal or metallized substrate; an undercoat layer comprising a polymerresin and a near infrared absorbing component that absorbs at an imagingmember exposure wavelength and has a high molar extinction coefficient;and one or more additional layers disposed on the undercoat layer,wherein the additional layer or layers comprise a charge-generatingcomponent and a charge-transport component. In embodiments, thecomponent is soluble in an undercoat layer solvent. In furtherembodiments, the dye can be insoluble or partially soluble and dispersedor otherwise disposed throughout the undercoat layer.

In embodiments, an imaging member is disclosed comprising a metal ormetallized substrate; an undercoat layer comprising a polymer resin anda near infrared absorbing dye that absorbs at an imaging member exposurewavelength of from about 750 to about 900 nanometers, has a molarextinction coefficient of from about 10³ to about 5×10⁶ and is solublein an undercoat layer solvent; and one or more additional layersdisposed on the undercoat layer, wherein the additional layer or layerscomprise a charge-generating component and a charge-transport component.

Embodiments disclosed herein further include an image forming apparatusfor forming images on a recording medium comprising a) a photoreceptormember having a charge retentive surface to receive an electrostaticlatent image thereon, wherein said photoreceptor member comprises aconductive substrate, an undercoat layer comprising a polymer resin anda near infrared region absorbing component having a high molarextinction coefficient, wherein the near infrared absorbing component issoluble in an undercoat layer solvent, a charge-generating layer, and acharge transport layer comprising charge transport materials dispersedtherein; b) a development component to apply a developer material tosaid charge-retentive surface to develop said electrostatic latent imageto form a developed image on said charge-retentive surface; c) atransfer component for transferring said developed image from saidcharge-retentive surface to another member or a copy substrate; and d) afusing member to fuse said developed image to said copy substrate.

DETAILED DESCRIPTION

In various exemplary embodiments of an electrophotographic imagingmember as disclosed herein, an imaging member includes a metal ormetallized substrate; an undercoat layer comprising a polymer resin anda near infrared absorbing component that absorbs at an imaging memberexposure wavelength and, in embodiments, has a high molar extinctioncoefficient, wherein in embodiments the component is soluble in anundercoat layer solvent; and one or more additional layers disposed onthe undercoat layer, wherein the additional layer or layers comprise acharge-generating component and a charge-transport component. The membermay optionally include other layers, such as an adhesive layer. Invarious exemplary embodiments, additional layers are present and arelocated between a substrate layer and a photoconductive orphotosensitive layer.

Also disclosed herein is an image forming apparatus for forming imageson a recording medium comprising a) a photoreceptor member having acharge retentive surface to receive an electrostatic latent imagethereon, wherein said photoreceptor member comprises a conductivesubstrate, an undercoat layer comprising a polymer resin and a nearinfrared region absorbing component having a high molar extinctioncoefficient, wherein the near infrared absorbing component is soluble inan undercoat layer solvent, a charge-generating layer, and a chargetransport layer comprising charge transport materials dispersed therein;b) a development component to apply a developer material to saidcharge-retentive surface to develop said electrostatic latent image toform a developed image on said charge-retentive surface; c) a transfercomponent for transferring said developed image from saidcharge-retentive surface to another member or a copy substrate; and d) afusing member to fuse said developed image to said copy substrate.

In embodiments, an undercoat layer is selected to include at least onematerial selected from resin material, such as polyethylene,polypropylene, polystyrene, acrylic resin, vinyl chloride resin, vinylacetate resin, polyurethane, epoxy resin, polyester, melamine resin,silicone resin, polyvinyl butyryl, polyamide, phenolic resin, copolymersthereof, mixtures thereof, and copolymers containing two or more ofrepeated units of these resins. Such resin materials also includecasein, gelatin, polyvinyl alcohol, ethyl cellulose, mixtures thereof,etc. Undercoat layers herein can be formed by any suitable method asknown in the art. Undercoat layers are typically formed, for example, bya dip coating process, such as the methods disclosed in, for example,U.S. Pat. Nos. 5,958,638 and 5,891,594, the disclosures of each of whichare totally incorporated by reference herein. In embodiments, theundercoat layer comprises a polymer resin and titanium dioxide. In aselected embodiment, the undercoat layer comprises a titanium dioxide,for example a titanium dioxide in a phenolic resin/melamine resin.

In embodiments, the undercoat layer comprises a thickness selected fromabout 0.1 to about 100 micrometers, from about 5 to about 20micrometers, or a thickness of about 5 micrometers. However, thicknessesoutside these ranges can be used, as desired.

Without wishing to be bound by theory, it is believed that variousexemplary embodiments disclosed herein reduce or eliminate ghost imagedefects on a printed image by removing trapped electrons and holesresiding in the imaging members. In embodiments disclosed herein,without wishing to be bound by theory, by providing an undercoat layerincluding a near infrared absorbing component, trapped electronsresiding predominately at or near the interface between the chargegenerating layer and the undercoat layer and holes residingpredominately at or near the interface between the charge generatinglayer and the charger transport layer are neutralized by free countercharges and dissipated to the top surface or substrate.

In various exemplary embodiments, the near infrared absorbing componenthas a strong absorption in a light wavelength range that matches anexposure wavelength used in the imaging process, such as in the exposurewavelength range of about 750 nanometers to about 900 nanometers. Forexample, selected near infrared absorbing components include hearinfrared dyes that absorb strongly around 780 nanometers, the mostcommon light exposure wavelength for xerography due to commerciallyavailable Ga_(1-x)Al_(x)A_(s) diode lasers.

Embodiments disclosed herein include an undercoat layer comprising anear infrared absorbing component which absorbs at an exposurewavelength of about 750 to about 900 nanometers, about 750 to about 800nanometers, or about 780 nanometers. Any suitable near infraredabsorbing components may be included in the undercoat layer of variousexemplary embodiments. Such near infrared absorbing components include,but are not limited to, for example, near infrared dyes which absorb atabout 750 to about 900 nanometers, about 750 to about 800 nanometers, orabout 780 nanometers.

In embodiments, the near infrared absorbing component selected for theundercoat layer has a molar extinction coefficient of about 10³ to about5×10⁶. In another selected embodiment, the near infrared absorbingcomponent selected for the undercoat layer has a molar extinctioncoefficient of greater than about 100,000 or greater than about 200,000.

The near infrared absorbing component is selected in embodiments at anamount of about 0.01 to about 20% by weight, or about 0.02 to about 10%by weight. or about 0.1 to about 5% by weight, or about 2% by weight,based upon the total weight of the undercoat layer.

Suitable dyes include in embodiments dyes that are dissolvable in thesolvent system of the undercoat layer, for example, typical undercoatlayer solvents including, but not limited to, xylene, butanol, ketones,alcohols, halogenated solvents, and the like.

In embodiments, the near infrared dyes selected include, but are notlimited to, for example, squaraines, aryldienes, aryltrienes, and metaldithiolene.

In further embodiments, the near infrared absorbing component includes amaterial commercially available from Crystalyn Chemical Company, havingthe following structure

wherein R₁, R₂, and R₃ can in embodiments be the same or different andcan be selected separately from about hydrocarbon having from about 1 toabout 30 carbons, for example alky, alkenyl, alkynyl, aryl, heterocyclicsubstituents, etc., for example, in embodimentsR₁ is selected as

-   -   and X⁻

wherein X⁻ is selected for example, from the group consisting of Br, Cl,ClO₄, BF₄.

In embodiments, the near infrared absorbing component is, for example,3-ethylidene-1-(ethenyl)cyclohexene.

In various exemplary embodiments, photoreceptors incorporating at leastone undercoat layer doped with at least one near infrared absorbingcomponent show excellent electrical properties with low dark decay, lowvoltage residue, and high photosensitivity.

The structure of a photoconductive member according to various exemplaryembodiments disclosed herein can follow any of various knownphotoreceptor designs, modified to include herein-described variousexemplary embodiments of undercoat or other layers. Becausephotoreceptor designs are well known in the art, the remaining layers ofthe imaging member, for example, photoreceptor will be described only inbrief detail for completeness.

In various exemplary embodiments, an imaging member comprises asupporting substrate, an undercoating layer, a photogenerating layer anda charge transport layer (which can be separate or combined into asingle photoconductor layer).

Optionally, an overcoat layer is added to improve resistance toabrasion. Further, a back coating can be selected and applied to theside opposite the imaging side of the photoreceptor to provide flatnessand/or abrasion resistance. These overcoat and back coat layers caninclude any suitable composition, such as, for example, organic polymersor inorganic polymers that are electrically insulating or slightlysemi-conductive.

In various exemplary embodiments, a photoconductive imaging member asdisclosed herein includes a supporting substrate, an undercoat layer, anadhesive layer, a photogenerating layer and a charge transport layer.These and other exemplary photoreceptor designs, which can be applied inembodiments of the disclosure, are described in, for example, U.S. Pat.Nos. 6,165,660, 3,357,989, 5,891,594, and 3,442,781, the entiredisclosures of which are incorporated herein by reference.

The supporting substrate can be selected to include a conductive metalsubstrate or a metallized substrate. While a metal substrate issubstantially or completely metal, the substrate of a metallizedsubstrate is made of a different material that has at least one layer ofmetal applied to at least one surface of the substrate. The material ofthe substrate of the metallized substrate can be any material for whicha metal layer is capable of being applied. For instance, the substratecan be a synthetic material, such as a polymer. In various exemplaryembodiments, a conductive substrate is, for example, at least one memberselected from the group consisting of aluminum, aluminized or titanizedpolyethylene terephthalate belt (MYLAR®).

Any metal or metal alloy can be selected for the metal or metallizedsubstrate. Typical metals employed for this purpose include aluminum,zirconium, niobium, tantalum, vanadium, hafnium, titanium, nickel,stainless steel, chromium, tungsten, molybdenum, mixtures andcombinations thereof, and the like. Useful metal alloys may contain twoor more metals such as zirconium, niobium, tantalum, vanadium, hafnium,titanium, nickel, stainless steel, chromium, tungsten, molybdenum,mixtures and combinations thereof, and the like. Aluminum, such asmirror-finish aluminum, is selected in embodiments for both the metalsubstrate and the metal in the metallized substrate. All types ofsubstrates may be used, including honed substrates, anodized substrates,bohmite-coated substrates and mirror substrates.

A metal substrate or metallized substrate can be selected. Examples ofsubstrate layers selected for the present imaging members include opaqueor substantially transparent materials, and may comprise any suitablematerial having the requisite mechanical properties. Thus, for example,the substrate can comprise a layer of insulating material includinginorganic or organic polymeric materials, such as Mylar®, a commerciallyavailable polymer, Mylar® containing titanium, a layer of an organic orinorganic material having a semiconductive surface layer, such as indiumtin oxide or aluminum arrange thereon, or a conductive material such asaluminum, chromium, nickel, brass or the like. The substrate may beflexible, seamless, or rigid, and may have a number of differentconfigurations. For example, the substrate may comprise a plate, acylindrical drum, a scroll, and endless flexible belt, or otherconfiguration. In some situations, it may be desirable to provide ananticurl layer to the back of the substrate, such as when the substrateis a flexible organic polymeric material, such as for examplepolycarbonate materials, for example Makrolon® a commercially availablematerial.

In various exemplary embodiments, the photogenerator layer has anysuitable thickness. In various exemplary embodiments, the photogeneratorlayer has a thickness of from about 0.05 micrometers to about 10micrometers. In various exemplary embodiments, the transport layer has athickness of from about 10 micrometers to about 50 micrometers. Invarious exemplary embodiments, the photogenerator layer includesphotogenerating pigments dispersed in a resinous binder in an amount offrom about 5 percent by weight to about 95 percent by weight. In variousexemplary embodiments, the resinous binder is any suitable binder. Invarious exemplary embodiments, the resinous binder is at least onemember selected from the group consisting of polyesters, polyvinylbutyrals, polycarbonates, polystyrene-b-polyvinyl pyridine, andpolyvinyl formals.

The charge-transport component transports charge from thecharge-generating layer to the surface of the photoreceptor. Often, thecharge-transport component is made up of several materials, includingelectrically active organic-resin materials such as polymeric arylaminecompounds, polysilylenes (such as poly(methylphenyl silylene),poly(methylphenyl silylene-co-dimethyl silylene), poly(cyclohexylmethylsilylene), and poly(cyanoethylmethyl silylene)), and polyvinyl pyrenes.The charge-transport component typically contains at least one compoundhaving an arylamine, enamine, or hydrazone group. The compoundcontaining the arylamine may be dispersed in a resinous binder, such asa polycarbonate or a polystyrene. In various exemplary embodiments, acharge transport layer can include aryl amine molecules. In variousexemplary embodiments, a charge transport layer can include aryl aminesof the following formula:

wherein Y is selected from the group consisting of alkyl and halogen,and wherein the aryl amine is dispersed in a highly insulating andtransparent resinous binder. In embodiments, halogen is selected, suchas for example fluorine, bromine, chlorine, and iodine. In variousexemplary embodiments, the arylamine alkyl contains from about 1 toabout 10 carbon atoms. In various exemplary embodiments, the arylaminealkyl contains from 1 to about 5 carbon atoms. In various exemplaryembodiments, the arylamine alkyl is methyl, the halogen is chlorine, andthe resinous binder is selected from the group consisting ofpolycarbonates and polystyrenes. A selected compound having an arylaminegroup is N,N′-diphenyl-N,N-bis(3-methylphenyl)-1,1′-biphenyl-4,4′-diamine.

The charge-generating component converts light input into electron holepairs. Examples of compounds suitable for use as the charge-generatingcomponent include vanadyl phthalocyanine, metal phthalocyanines (such astitanyl phthalocyanine, chlorogallium phthalocyanine, hydroxygalliumphthalocyanine, and alkoxygallium phthalocyanine), metal-freephthalocyanines, benzimidazole perylene, amorphous selenium, trigonalselenium, selenium alloys (such as selenium-tellurium,selenium-tellurium arsenic, selenium arsenide), chlorogalliumphthalocyanin, and mixtures and combinations thereof. In variousexemplary embodiments, a photogenerating layer includes metalphthalocyanines and/or metal free phthalocyanines. In various exemplaryembodiments, a photogenerating layer includes at least onephthalocyanine selected from the group consisting of titanylphthalocyanines, perylenes, or hydroxygallium phthalocyanines. Invarious exemplary embodiments, a photogenerating layer includes Type Vhydroxygallium phthalocyanine.

The additional layers containing the charge-transport component and thecharge-generating component may be applied as a single layer or may beapplied separately as two distinct layers. The decision of whether toapply the components as a single layer or separate layers lies withinthe preference of the skilled artisan. Traditionally, the components areapplied as separate layers; however, applying the components as a singlelayer may prove more convenient, cheaper, and may result in anelectrophotographic-imaging member that is thinner or contains otherdesirable properties. The additional layers, whether as a single layeror separate layers, may be applied by techniques known to those in theart, such as chemical vaporization, sputtering, spraying, dipping, andspin-and-roller coating.

The additional layer or layers containing the charge-transport andcharge-generating components can include various other materials, suchas binder polymeric resin materials, film-including particles, or resinlayers having a photoconductive material. If the charge-transportcomponent and charge-generating component are applied in separatelayers, the layer containing the charge-generating component willtypically contain the resinous binder composition. Suitable polymericfilm-forming binder materials include, but are not limited to,thermoplastic and thermosetting resins, such as polycarbonates,polyesters, polyamides, polyurethanes, polystyrenes, polyarylethers,polyarylsulfones, polybutadienes, polysulfones, polyethersulfones,polyethylenes, polypropylenes, polyimides, polymethylpentenes,polyphenylene sulfides, polyvinyl acetate, polysiloxanes, polyacrylates,polyvinyl acetals, amino resins, phenylene oxide resins, terephthalicacid resins, phenoxy resins, epoxy resins, phenolic resins, polystyreneand acrylonitrile copolymers, polyvinyl chloride, vinylchloride andvinyl acetate copolymers, acrylate copolymers, alkyd resins, cellulosicfilm formers, poly(amideimide), styrene-butadiene copolymers,vinylidinechloride-vinylchloride copolymers,vinylacetate-vinylidenechloride copolymers,vinylacetate-vinylidenechloride copolymers, styrene-alkyd resins,polyvinylcarbazole, and mixtures thereof.

The charge-generating component may also contain a photogeneratingcomposition or pigment. The photogenerating composition or pigment maybe present in the resinous binder composition in various amounts,ranging from about 5% by volume to about 90% by volume (thephotogenerating pigment is dispersed in about 10% by volume to about 95%by volume of the resinous binder); or from about 20% by volume to about30% by volume (the photogenerating pigment is dispersed in about 70% byvolume to about 80% by volume of the resinous binder composition). Inone embodiment, about 8 percent by volume of the photogenerating pigmentis dispersed in about 92 percent by volume of the resinous bindercomposition. When the photogenerating component contains photoconductivecompositions and/or pigments in the resinous binder material, thethickness of the layer typically ranges from about 0.1 μm to about 5.0μm, or from about 0.3 μm to about 3 μm. The photogenerating layerthickness is often related to binder content, for example, higher bindercontent compositions typically require thicker layers forphotogeneration. Thicknesses outside these ranges may also be selected.

The thickness of the device typically ranges from about 2 μm to about100 μm; from about 5 μm to about 50 μm, or from about 10 μm to about 30μm. The thickness of each layer will depend on how many components arecontained in that layer, how much of each component is desired in thelayer, and other factors familiar to those in the art. If thecharge-generating component and charge-transport component are appliedin separate layers, the ratio of the thickness of the layer containingthe charge-transport component to the layer containing thecharge-generating component typically ranges from about 2:1 to about400:1, or from about 2:1 to about 200:1.

Various exemplary embodiments encompassed herein include a method ofimaging which includes generating an electrostatic latent image on animaging member, developing a latent image, and transferring thedeveloped electrostatic image to a suitable substrate.

Further embodiments encompassed within the present disclosure includemethods of imaging and printing with the photoresponsive devicesillustrated herein. Various exemplary embodiments include methodsincluding forming an electrostatic latent image on an imaging member;developing the image with a toner composition including, for example, atleast one thermoplastic resin, at least one colorant, such as pigment,at least one charge additive, and at least one surface additive;transferring the image to a necessary member, such as, for example anysuitable substrate, such as, for example, paper; and permanentlyaffixing the image thereto. In various exemplary embodiments in whichthe embodiment is used in a printing mode, various exemplary imagingmethods include forming an electrostatic latent image on an imagingmember by use of a laser device or image bar; developing the image witha toner composition including, for example, at least one thermoplasticresin, at least one colorant, such as pigment, at least one chargeadditive, and at least one surface additive; transferring the image to anecessary member, such as, for example any suitable substrate, such as,for example, paper; and permanently affixing the image thereto.

EXAMPLES

The following Examples are being submitted to further define variousspecies of the present disclosure. These Examples are intended to beillustrative only and are not intended to limit the scope of the presentdisclosure. Also, parts and percentages are by weight unless otherwiseindicated.

Example I

An undercoat layer was prepared comprising 13.26 grams of titanium oxide(MT-150W available from Tayca Corporation), 4.4 grams phenolic resin(Varcuum 29159 available from Oxychem Corporation), and 6.5 gramsmelamine resin (Cymel® 323 available from Cytec Corporation) at a 63:37pigment to binder weight ration and a 70:30 Varcuum to Cymel® 323 weightratio. The undercoat layer was doped with 0.16 grams (0.8% by weight)ET259 near infrared dye available from Crystalyn Chemical Company. Theundercoat layer was cured at 145° C. for 40 minutes. A 4 micrometerslayer of the undercoat layer was disposed over an aluminum substrate. Aphotoreceptive imaging member was prepared by disposing a 0.2 to 0.5micrometer thick charge generating comprising chlorogalliumphthalocyanine and a vinyl resin binder at a pigment to binder weightratio of about 60 to 40 and a 29 micrometer thick charge transport layercomprising N,N′-bis(methylphenyl)-1,1-biphenyl-4,4′-diamine, apolycarbonate binder, and PTFE particles as a weight ratio of 36.4 to54.5 to 9.1, respectively.

Example II

An undercoat layer was prepared comprising 13.26 grams of titanium oxide(MT-150W available from Tayca Corporation), 4.4 grams phenolic resin(Varcuum 29159 available from Oxychem Corporation), and 6.5 gramsmelamine resin (Cymel® 323 available from Cytec Corporation) at a 63:37pigment to binder weight ration and a 70:30 Varcuum to Cymel® 323 weightratio. The undercoat layer was doped with 0.16 grams (0.8% by weight)ET457 near infrared dye available from Crystalyn Chemical Company. Theundercoat layer was cured at 145° C. for 40 minutes. A 4 micrometersthick undercoat layer was disposed over an aluminum substrate. Aphotoreceptive imaging member was prepared by disposing a 0.2 to 0.5micrometer thick charge generating comprising chlorogalliumphthalocyanine and a vinyl resin binder at a pigment to binder weightratio of about 60 to 40 and a 29 micrometer thick charge transport layercomprising N,N′-bis(methylphenyl)-1,1-biphenyl-4,4′-diamine, apolycarbonate binder, and PTFE particles as a weight ratio of 36.4 to54.5 to 9.1, respectively.

Comparative Example I

An undercoat layer was prepared comprising 13.26 grams of titanium oxide(MT-150W available from Tayca Corporation), 4.4 grams phenolic resin(Varcuum 29159 available from Oxychem Corporation), and 6.5 gramsmelamine resin (Cymel® 323 available from Cytec Corporation) at a 63:37pigment to binder weight ration and a 70:30 Varcuum to Cymel® 323 weightratio. The undercoat layer was not doped with near infrared redabsorbing dye. The undercoat layer was cured at 145° C. for 40 minutes.A 4 micrometer thick undercoat layer was disposed over an aluminumsubstrate. A photoreceptive imaging member was prepared by disposing a0.2 to 0.5 micrometer thick charge generating comprising chlorogalliumphthalocyanine and a vinyl resin binder at a pigment to binder weightratio of about 60 to 40 and a 29 micrometer thick charge transport layercomprising N,N′-bis(methylphenyl)-1,1-biphenyl-4,4′-diamine, apolycarbonate binder and PTFE particles as a weight ratio of 36.4 to54.5 to 9.1, respectively.

The devices were acclimated for 24 hours before testing in J zone (70°F., 10% relative humidity). Print samples were prepared for each deviceon a Copeland Work Center Pro 3545 device using black and white copymode and a machine speed of 208 mm. Ghosting levels were measuredagainst an image standard of ghosting grades from 0-5. The printingprotocol comprised 1) printing ghost target at the start of test (t=0);2) printing 200 documents using a 5% area coverage; 3) printing ghosttarget after 200 documents; and 4) visually evaluating the printeddocuments comparing to the image standard. Test results are provided inTable 1. TABLE 1 Example Number Zone Ghost T = 0 Ghost T = 200 1 J −2 −32 J −2 −3.5 Comparative Example 1 J −3 −5

It will be appreciated that various of the above-discussed and otherfeatures and functions, or alternatives thereof, may be desirablycombined into many other different systems or applications. Also thatvarious presently unforeseen or unanticipated alternatives,modifications, variations or improvements therein may be subsequentlymade by those skilled in the art which are also intended to beencompassed by the following claims.

1. An imaging member comprising: a metal or metallized substrate; an undercoat layer comprising a polymer resin and a near infrared absorbing component that absorbs at an imaging member exposure wavelength and has a high molar extinction coefficient; and one or more additional layers disposed on the undercoat layer, wherein the additional layer or layers comprise a charge-generating component and a charge-transport component.
 2. The imaging member of claim 1, wherein the near infrared absorbing component absorbs at an exposure wavelength of from about 750 to about 900 nanometers.
 3. The imaging member of claim 1, wherein the near infrared absorbing component absorbs at an exposure wavelength of from about 750 to about 800 nanometers.
 4. The imaging member of claim 1, wherein the near infrared absorbing component absorbs at an exposure wavelength of about 780 nanometers.
 5. The imaging member of claim 1, wherein the near infrared absorbing component has a molar extinction coefficient of from about 10³ to about 5×10⁶.
 6. The imaging member of claim 1, wherein the near infrared absorbing component has a molar extinction coefficient of greater than about 100,000.
 7. The imaging member of claim 1, wherein the near infrared absorbing component is selected in an amount of from about 0.01 to about 20 percent by weight based upon the total weight of the undercoat layer.
 8. The imaging member of claim 1, wherein the near infrared absorbing component is selected in an amount of from about 0.1 to about 5 percent by weight based upon the total weight of the undercoat layer.
 9. The imaging member of claim 1, wherein the near infrared absorbing component comprises a dye selected from the group consisting of squaraines, aryldienes, aryltrienes, and metal dithiolene.
 10. The imaging member of claim 1, wherein the near infrared absorbing component comprises a material having the structure

wherein R₁, R₂, and R₃ are the same or different and are selected separately from hydrocarbon having from about 1 to about 30 carbons, alky, alkenyl, alkynyl, aryl, and heterocyclic substituents; and wherein Z is selected from the group consisting of

and X⁻ wherein X⁻ is selected from the group consisting of Br, C1, ClO₄, and BF₄.
 11. The imaging member of claim 1, wherein the near infrared absorbing component comprises a material having the structure

and X⁻ wherein X⁻ is selected from the group consisting of Br, Cl, ClO₄, and BF₄.
 12. The imaging member of claim 1, wherein the polymer resin comprises at least one resin selected from the group consisting of polyethylenes, polypropylenes, polystyrenes, acrylic resins, vinyl chloride resins, vinyl acetate resins, polyurethanes, epoxy resins, polyesters, melamine resins, silicone resins, polyvinyl butyryls, polyamides, phenolic resins, copolymers thereof, and mixtures thereof.
 13. The imaging member of claim 1, wherein the polymer resin further comprises at least one additional material selected from the group consisting of caseins, gelatins, polyvinyl alcohols, ethyl celluloses and mixtures thereof.
 14. The imaging member of claim 1, wherein the undercoat layer further comprises titanium dioxide.
 15. The method of claim 1, wherein the undercoat layer further comprises a titanium dioxide in a phenolic resin/melamine resin
 16. The imaging member of claim 1, wherein the undercoat layer has a thickness of from about 0.1 micrometers to about 100 micrometers.
 17. The imaging member of claim 1, wherein the charge-transport component comprises at least one compound having an arylamine group, an enamine group, a hydrazone group, or a combination thereof.
 18. The imaging member of claim 1, wherein the charge-generating component comprises a material selected from the group consisting of vanadyl phthalocyanine, metal phthalocyanines, metal-free phthalocyanine, hydroxygallium phthalocyanine, benzimidazole perylene, amorphous selenium, trigonal selenium, selenium alloys, chlorogallium phthalocyanin, mixtures thereof, and combinations thereof.
 19. The imaging member of claim 1, wherein the metal or metallized substrate comprises aluminum, zirconium, niobium, tantalum, vanadium, hafnium, titanium, nickel, stainless steel, chromium, tungsten, molybdenum, metal alloys comprising two or more metals selected from the group comprising zirconium, niobium, tantalum, vanadium and hafnium, titanium, nickel, stainless steel, chromium, tungsten, molybdenum, mixtures thereof, and combinations thereof.
 20. The method of claim 1, wherein the metal or metallized substrate comprises aluminum.
 21. An imaging member comprising: a metal or metallized substrate; an undercoat layer comprising a polymer resin and a near infrared absorbing dye that absorbs at an imaging member exposure wavelength of from about 750 to about 900 nanometers, has a molar extinction coefficient of from about 10³ to about 5×10⁶ and is soluble in an undercoat layer solvent; and one or more additional layers disposed on the undercoat layer, wherein the additional layer or layers comprise a charge-generating component and a charge-transport component.
 22. An image forming apparatus for forming images on a recording medium comprising: a) a photoreceptor member having a charge retentive surface to receive an electrostatic latent image thereon, wherein said photoreceptor member comprises a conductive substrate, an undercoat layer comprising a polymer resin and a near infrared region absorbing component having a high molar extinction coefficient, wherein the near infrared absorbing component is soluble in an undercoat layer solvent, a charge-generating layer, and a charge transport layer comprising charge transport materials dispersed therein; b) a development component to apply a developer material to said charge-retentive surface to develop said electrostatic latent image to form a developed image on said charge-retentive surface; c) a transfer component for transferring said developed image from said charge-retentive surface to another member or a copy substrate; and d) a fusing member to fuse said developed image to said copy substrate. 